What happens when a revolution lasts for several decades? It becomes the status quo.
The next revolution in Cuba, now that Fidel Castro has stepped down as its head of state, will likely be an economic one. His successor, Raul Castro (yes, they're related), is known to favor a slight liberalization of the economy.
If the U.S. is smart, it will dump sanctions and the embargo and take advantage of any free-market leanings of Fidel's successor. The best hope for democratizing Cuba isn't another revolution, but to make inroads via the economy. Because change isn't likely to come with a continuation of the status quo.
Political dissidents will not have any more leeway under a Raul regime than they did under Castro. Some commentators have called Raul, the country's military leader, "the most feared man" on the island. His ascension to power was smooth and planned. He won't rock the boat on his own. But the influx of U.S. economic stimulus that would come from lifting sanctions might create enough waves so that he has no choice.
So presidential candidates, take note: Unless the status quo is altered, there will be no change in Cuba.